defender-security / extra / hub-connector / lib / PHPSecLib / Crypt / Random.php

Random.php in Defender Security – Malware Scanner, Login Security & Firewall 6.3.0, at extra/hub-connector/lib/PHPSecLib/Crypt/Random.php

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1	<?php
2
3	/**
4	* Random Number Generator
5	*
6	* The idea behind this function is that it can be easily replaced with your own crypt_random_string()
7	* function. eg. maybe you have a better source of entropy for creating the initial states or whatever.
8	*
9	* PHP versions 4 and 5
10	*
11	* Here's a short example of how to use this library:
12	* <code>
13	* <?php
14	* include 'Crypt/Random.php';
15	*
16	* echo bin2hex(crypt_random_string(8));
17	* ?>
18	* </code>
19	*
20	* LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
21	* of this software and associated documentation files (the "Software"), to deal
22	* in the Software without restriction, including without limitation the rights
23	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
24	* copies of the Software, and to permit persons to whom the Software is
25	* furnished to do so, subject to the following conditions:
26	*
27	* The above copyright notice and this permission notice shall be included in
28	* all copies or substantial portions of the Software.
29	*
30	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
31	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
32	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
33	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
34	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
35	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
36	* THE SOFTWARE.
37	*
38	* @category Crypt
39	* @package Crypt_Random
40	* @author Jim Wigginton <[email protected]>
41	* @copyright 2007 Jim Wigginton
42	* @license http://www.opensource.org/licenses/mit-license.html MIT License
43	* @link http://phpseclib.sourceforge.net
44	*/
45
46	// laravel is a PHP framework that utilizes phpseclib. laravel workbenches may, independently,
47	// have phpseclib as a requirement as well. if you're developing such a program you may encounter
48	// a "Cannot redeclare crypt_random_string()" error.
49	if (!function_exists('crypt_random_string')) {
50	/**
51	* "Is Windows" test
52	*
53	* @access private
54	*/
55	define('CRYPT_RANDOM_IS_WINDOWS', strtoupper(substr(PHP_OS, 0, 3)) === 'WIN');
56
57	/**
58	* Generate a random string.
59	*
60	* Although microoptimizations are generally discouraged as they impair readability this function is ripe with
61	* microoptimizations because this function has the potential of being called a huge number of times.
62	* eg. for RSA key generation.
63	*
64	* @param int $length
65	* @return string
66	* @access public
67	*/
68	function crypt_random_string($length)
69	{
70	if (!$length) {
71	return '';
72	}
73
74	if (CRYPT_RANDOM_IS_WINDOWS) {
75	// method 1. prior to PHP 5.3, mcrypt_create_iv() would call rand() on windows
76	if (extension_loaded('mcrypt') && version_compare(PHP_VERSION, '5.3.0', '>=')) {
77	return @mcrypt_create_iv($length);
78	}
79	// method 2. openssl_random_pseudo_bytes was introduced in PHP 5.3.0 but prior to PHP 5.3.4 there was,
80	// to quote <http://php.net/ChangeLog-5.php#5.3.4>, "possible blocking behavior". as of 5.3.4
81	// openssl_random_pseudo_bytes and mcrypt_create_iv do the exact same thing on Windows. ie. they both
82	// call php_win32_get_random_bytes():
83	//
84	// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/openssl/openssl.c#L5008
85	// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/mcrypt/mcrypt.c#L1392
86	//
87	// php_win32_get_random_bytes() is defined thusly:
88	//
89	// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/win32/winutil.c#L80
90	//
91	// we're calling it, all the same, in the off chance that the mcrypt extension is not available
92	if (extension_loaded('openssl') && version_compare(PHP_VERSION, '5.3.4', '>=')) {
93	return openssl_random_pseudo_bytes($length);
94	}
95	} else {
96	// method 1. the fastest
97	if (extension_loaded('openssl') && version_compare(PHP_VERSION, '5.3.0', '>=')) {
98	return openssl_random_pseudo_bytes($length);
99	}
100	// method 2
101	static $fp = true;
102	if ($fp === true) {
103	// warning's will be output unles the error suppression operator is used. errors such as
104	// "open_basedir restriction in effect", "Permission denied", "No such file or directory", etc.
105	$fp = @fopen('/dev/urandom', 'rb');
106	}
107	if ($fp !== true && $fp !== false) { // surprisingly faster than !is_bool() or is_resource()
108	$temp = fread($fp, $length);
109	if (strlen($temp) == $length) {
110	return $temp;
111	}
112	}
113	// method 3. pretty much does the same thing as method 2 per the following url:
114	// https://github.com/php/php-src/blob/7014a0eb6d1611151a286c0ff4f2238f92c120d6/ext/mcrypt/mcrypt.c#L1391
115	// surprisingly slower than method 2. maybe that's because mcrypt_create_iv does a bunch of error checking that we're
116	// not doing. regardless, this'll only be called if this PHP script couldn't open /dev/urandom due to open_basedir
117	// restrictions or some such
118	if (extension_loaded('mcrypt')) {
119	return @mcrypt_create_iv($length, MCRYPT_DEV_URANDOM);
120	}
121	}
122	// at this point we have no choice but to use a pure-PHP CSPRNG
123
124	// cascade entropy across multiple PHP instances by fixing the session and collecting all
125	// environmental variables, including the previous session data and the current session
126	// data.
127	//
128	// mt_rand seeds itself by looking at the PID and the time, both of which are (relatively)
129	// easy to guess at. linux uses mouse clicks, keyboard timings, etc, as entropy sources, but
130	// PHP isn't low level to be able to use those as sources and on a web server there's not likely
131	// going to be a ton of keyboard or mouse action. web servers do have one thing that we can use
132	// however, a ton of people visiting the website. obviously you don't want to base your seeding
133	// soley on parameters a potential attacker sends but (1) not everything in $_SERVER is controlled
134	// by the user and (2) this isn't just looking at the data sent by the current user - it's based
135	// on the data sent by all users. one user requests the page and a hash of their info is saved.
136	// another user visits the page and the serialization of their data is utilized along with the
137	// server envirnment stuff and a hash of the previous http request data (which itself utilizes
138	// a hash of the session data before that). certainly an attacker should be assumed to have
139	// full control over his own http requests. he, however, is not going to have control over
140	// everyone's http requests.
141	static $crypto = false, $v;
142	if ($crypto === false) {
143	// save old session data
144	$old_session_id = session_id();
145	$old_use_cookies = ini_get('session.use_cookies');
146	$old_session_cache_limiter = session_cache_limiter();
147	$_OLD_SESSION = isset($_SESSION) ? $_SESSION : false;
148	if ($old_session_id != '') {
149	session_write_close();
150	}
151
152	session_id(1);
153	ini_set('session.use_cookies', 0);
154	session_cache_limiter('');
155	session_start();
156
157	$v = $seed = $_SESSION['seed'] = pack('H*', sha1(
158	(isset($_SERVER) ? phpseclib_safe_serialize($_SERVER) : '') .
159	(isset($_POST) ? phpseclib_safe_serialize($_POST) : '') .
160	(isset($_GET) ? phpseclib_safe_serialize($_GET) : '') .
161	(isset($_COOKIE) ? phpseclib_safe_serialize($_COOKIE) : '') .
162	// as of PHP 8.1 $GLOBALS can't be accessed by reference, which eliminates
163	// the need for phpseclib_safe_serialize. see https://wiki.php.net/rfc/restrict_globals_usage
164	// for more info
165	(version_compare(PHP_VERSION, '8.1.0', '>=') ? serialize($GLOBALS) : phpseclib_safe_serialize($GLOBALS)) .
166	phpseclib_safe_serialize($_SESSION) .
167	phpseclib_safe_serialize($_OLD_SESSION)
168	));
169	if (!isset($_SESSION['count'])) {
170	$_SESSION['count'] = 0;
171	}
172	$_SESSION['count']++;
173
174	session_write_close();
175
176	// restore old session data
177	if ($old_session_id != '') {
178	session_id($old_session_id);
179	session_start();
180	ini_set('session.use_cookies', $old_use_cookies);
181	session_cache_limiter($old_session_cache_limiter);
182	} else {
183	if ($_OLD_SESSION !== false) {
184	$_SESSION = $_OLD_SESSION;
185	unset($_OLD_SESSION);
186	} else {
187	unset($_SESSION);
188	}
189	}
190
191	// in SSH2 a shared secret and an exchange hash are generated through the key exchange process.
192	// the IV client to server is the hash of that "nonce" with the letter A and for the encryption key it's the letter C.
193	// if the hash doesn't produce enough a key or an IV that's long enough concat successive hashes of the
194	// original hash and the current hash. we'll be emulating that. for more info see the following URL:
195	//
196	// http://tools.ietf.org/html/rfc4253#section-7.2
197	//
198	// see the is_string($crypto) part for an example of how to expand the keys
199	$key = pack('H*', sha1($seed . 'A'));
200	$iv = pack('H*', sha1($seed . 'C'));
201
202	// ciphers are used as per the nist.gov link below. also, see this link:
203	//
204	// http://en.wikipedia.org/wiki/Cryptographically_secure_pseudorandom_number_generator#Designs_based_on_cryptographic_primitives
205	switch (true) {
206	case phpseclib_resolve_include_path('Crypt/AES.php'):
207	if (!class_exists('Crypt_AES')) {
208	require_once dirname(__FILE__).'/AES.php';
209	}
210	$crypto = new Crypt_AES(CRYPT_AES_MODE_CTR);
211	break;
212	case phpseclib_resolve_include_path('Crypt/Twofish.php'):
213	if (!class_exists('Crypt_Twofish')) {
214	require_once dirname(__FILE__).'/Twofish.php';
215	}
216	$crypto = new Crypt_Twofish(CRYPT_TWOFISH_MODE_CTR);
217	break;
218	case phpseclib_resolve_include_path('Crypt/Blowfish.php'):
219	if (!class_exists('Crypt_Blowfish')) {
220	require_once dirname(__FILE__).'/Blowfish.php';
221	}
222	$crypto = new Crypt_Blowfish(CRYPT_BLOWFISH_MODE_CTR);
223	break;
224	case phpseclib_resolve_include_path('Crypt/TripleDES.php'):
225	if (!class_exists('Crypt_TripleDES')) {
226	require_once dirname(__FILE__).'/TripleDES.php';
227	}
228	$crypto = new Crypt_TripleDES(CRYPT_DES_MODE_CTR);
229	break;
230	case phpseclib_resolve_include_path('Crypt/DES.php'):
231	if (!class_exists('Crypt_DES')) {
232	require_once dirname(__FILE__).'/DES.php';
233	}
234	$crypto = new Crypt_DES(CRYPT_DES_MODE_CTR);
235	break;
236	case phpseclib_resolve_include_path('Crypt/RC4.php'):
237	if (!class_exists('Crypt_RC4')) {
238	require_once dirname(__FILE__).'/RC4.php';
239	}
240	$crypto = new Crypt_RC4();
241	break;
242	default:
243	user_error('crypt_random_string requires at least one symmetric cipher be loaded');
244	return false;
245	}
246
247	$crypto->setKey($key);
248	$crypto->setIV($iv);
249	$crypto->enableContinuousBuffer();
250	}
251
252	//return $crypto->encrypt(str_repeat("\0", $length));
253
254	// the following is based off of ANSI X9.31:
255	//
256	// http://csrc.nist.gov/groups/STM/cavp/documents/rng/931rngext.pdf
257	//
258	// OpenSSL uses that same standard for it's random numbers:
259	//
260	// http://www.opensource.apple.com/source/OpenSSL/OpenSSL-38/openssl/fips-1.0/rand/fips_rand.c
261	// (do a search for "ANS X9.31 A.2.4")
262	$result = '';
263	while (strlen($result) < $length) {
264	$i = $crypto->encrypt(microtime()); // strlen(microtime()) == 21
265	$r = $crypto->encrypt($i ^ $v); // strlen($v) == 20
266	$v = $crypto->encrypt($r ^ $i); // strlen($r) == 20
267	$result.= $r;
268	}
269	return substr($result, 0, $length);
270	}
271	}
272
273	if (!function_exists('phpseclib_safe_serialize')) {
274	/**
275	* Safely serialize variables
276	*
277	* If a class has a private __sleep() method it'll give a fatal error on PHP 5.2 and earlier.
278	* PHP 5.3 will emit a warning.
279	*
280	* @param mixed $arr
281	* @access public
282	*/
283	function phpseclib_safe_serialize(&$arr)
284	{
285	if (is_object($arr)) {
286	return '';
287	}
288	if (!is_array($arr)) {
289	return serialize($arr);
290	}
291	// prevent circular array recursion
292	if (isset($arr['__phpseclib_marker'])) {
293	return '';
294	}
295	$safearr = array();
296	$arr['__phpseclib_marker'] = true;
297	foreach (array_keys($arr) as $key) {
298	// do not recurse on the '__phpseclib_marker' key itself, for smaller memory usage
299	if ($key !== '__phpseclib_marker') {
300	$safearr[$key] = phpseclib_safe_serialize($arr[$key]);
301	}
302	}
303	unset($arr['__phpseclib_marker']);
304	return serialize($safearr);
305	}
306	}
307
308	if (!function_exists('phpseclib_resolve_include_path')) {
309	/**
310	* Resolve filename against the include path.
311	*
312	* Wrapper around stream_resolve_include_path() (which was introduced in
313	* PHP 5.3.2) with fallback implementation for earlier PHP versions.
314	*
315	* @param string $filename
316	* @return string\|false
317	* @access public
318	*/
319	function phpseclib_resolve_include_path($filename)
320	{
321	if (function_exists('stream_resolve_include_path')) {
322	return stream_resolve_include_path($filename);
323	}
324
325	// handle non-relative paths
326	if (file_exists($filename)) {
327	return realpath($filename);
328	}
329
330	$paths = PATH_SEPARATOR == ':' ?
331	preg_split('#(?<!phar):#', get_include_path()) :
332	explode(PATH_SEPARATOR, get_include_path());
333	foreach ($paths as $prefix) {
334	// path's specified in include_path don't always end in /
335	$ds = substr($prefix, -1) == DIRECTORY_SEPARATOR ? '' : DIRECTORY_SEPARATOR;
336	$file = $prefix . $ds . $filename;
337	if (file_exists($file)) {
338	return realpath($file);
339	}
340	}
341
342	return false;
343	}
344	}
345